GT-40p!

The GT40-P heads are great as they are, although for any performance use at all you'll need to install better valve springs. Posted with a valve job is even better if you have the budget. Springs are a must. I use BBK unequal length shorty headers with 90 degree plug boots. Due to the different spark plug angle you'll need Ford racing headers made to accommodate these heads, or as I stated, get plug wires with 90 degree plug boots and you should be fine if you have unequal length shorty headers. Equal length can be a mild nightmare. The heads themselves, though are great.